“Europeans cannot assume that America’s military presence on the continent will last forever.” When Secretary of Defense Pete Hegseth issued that warning in February, he captured Europe’s strategic predicament with blunt precision. European governments know they must carry more of the security burden, and initiatives like the ReArm Europe plan show they’ve begun to act. Yet there remains a practical way for the United States to stay meaningfully engaged—effectively and at manageable cost—without recreating a Cold War–style footprint: Permanent Structured Cooperation, better known as PESCO.

PESCO’s mandate is both clear and demanding. It is “a treaty-based framework for the 26 participating Member States to jointly plan, develop, and invest in collaborative capability development and to enhance the operational readiness and contribution of armed forces.” That tidy sentence must operate within a union marked by uneven defense industries, divergent threat perceptions, and very real political constraints. The instrument is deliberately pragmatic: roughly seventy-five projects, each with a coordinating nation and opt-in partners, parcel out work across land, maritime, and air platforms as well as cyber and space.

Nor is this a stack of white papers gathering dust. In 2022, the European Medical Command reached full operational capability and merged with NATO’s Framework Nations Concept Multinational Medical Coordination Centre, forming the MMCC/EMC—a European-led effort that produced efficiencies directly strengthening NATO, and by extension, the United States. Against that backdrop, Washington has two strong reasons to engage more deeply.

First, the United States is already inside the tent. It participates in the Dutch-led Military Mobility (MM) project, the logistical backbone for any rapid-reinforcement scenario—think a Baltic contingency involving Russia. The goal is deceptively simple: “simplify and standardize cross-border military transport procedures” so allied troops and matériel can move at the speed events demand.

Canada and Norway—neither a member of the EU—are also involved, underscoring both the project’s utility and PESCO’s flexibility. Crucially, the Council of the European Union can invite third states to join specific projects where they add value, and it has done so. That mechanism offers a disciplined channel for American involvement that enhances readiness without locking in a permanent force structure.

Second, deeper U.S. participation aligns with Washington’s stated approach: Europeans should lead on their own defense, while the United States provides targeted expertise and niche enablers rather than permanent forward mass. From a European vantage point, that model preserves an American presence and tempers anxieties about a transatlantic rupture—concerns reflected in recent polling. From an American perspective, it sustains influence, interoperability, and visibility into complementary capability development while keeping the bill and the footprint within reason. In other words, PESCO can be a vehicle for burden-shifting that does not become burden-shedding.

Skeptics point to the prevailing mood—“America First”—and argue it implies fewer European commitments. But “America First” does not mean “America absent,” especially within a bounded, results-oriented framework like PESCO. A 2020 Council decision explicitly allows third-state participation when it brings “technical expertise or additional capabilities, including operational or financial support,” directly advancing PESCO’s aims. There is no requirement to bankroll projects; the United States can contribute know-how and specific enablers—precisely the role it already plays in Military Mobility. And while the rules sensibly guard against creating dependence on a third state for procurement, research, or capability development, American participation would still give U.S. planners and industry useful sightlines into efforts such as “Quantum Enablers for Strategic Advantage (QUEST)” and “Timely Warning and Interception with Space-based Theater surveillance (TWISTER).” In practice, that means learning from and shaping European workstreams without owning them.

Europe’s security architecture—and America’s role within it—is evolving. Washington will continue to prioritize the Indo-Pacific and long-term competition with China. Europe, for its part, has internalized the lesson that it must finance and field more of its own defense. Those priorities need not collide. Where interests overlap and efficiencies are real, disciplined cooperation is a sound strategy. PESCO—flexible, practical, and forward-looking—offers something close to a best-of-both-worlds bargain: Europe takes the lead and builds capacity; the United States remains present, influential, and interoperable—without overextension.